Phuwiangosaurus (meaning "Phu Wiang lizard") is the name given to a genus of dinosaur from the Early Cretaceous. It was a titanosaur which lived in Thailand. The type species, P. sirindhornae, was described by Martin, Buffetaut, and Suteethorn in 1994; it was named to honour Princess Maha Chakri Sirindhorn of Thailand, who was interested in the geology and palaeontology of Thailand. It was around 27.1 m (90 feet) long.